How do I save output in a file and get it back

[samer-alisaleh]

Hi,

Im trying to execute code that will create plot chart using python matplotlib, what is the best way to get the output ? I tried saving the file but it seems the file is going to get lost after the execution is done.

Thanks

[Brikaa]

The current way to do this is to manually output the file as base64.

[samer-alisaleh]

Thank you for quick reply. I have tried that with simple plot but I keep getting "stdout length exceeded" .

Here is my API call with the body:

http://localhost:2000/api/v2/execute

Body:

{
    "language": "python",
    "version": "3.11.0",
    "files": [
        
        {
            "name": "test.py",
            "content": "import matplotlib.pyplot as plt\nimport io\nimport base64\nimport sys\n# Create a sample plot\nplt.plot([1, 2, 3], [4, 5, 6])\n# Save the plot to a BytesIO buffer\nbuf = io.BytesIO()\nplt.savefig(buf, format='png')\nplt.close()\n# Encode the buffer to base64\ndata = base64.b64encode(buf.getvalue()).decode('utf-8')\n# Print the base64 string to stdout\nsys.stdout.write(data)\nsys.stdout.flush()"
            
        }
        
    ],
    "stdin": "",
    "args": ["1", "2", "3"],
    "compile_timeout": 0,
    "run_timeout": 0,
    "compile_cpu_time": 0,
    "run_cpu_time": 0,
    "compile_memory_limit": -1,
    "run_memory_limit": -1
}

Response:

{
    "run": {
        "signal": "SIGKILL",
        "stdout": "",
        "stderr": "Sandbox keeper received fatal signal 6\n",
        "code": null,
        "output": "Sandbox keeper received fatal signal 6\n",
        "memory": null,
        "message": "stdout length exceeded",
        "status": "OL",
        "cpu_time": 1681,
        "wall_time": 3210
    },
    "language": "python",
    "version": "3.11.0"
}

Im not sure if there is a way to change the stdout limit. is there?
Thanks for your help
S

[Brikaa]

It is configured through the PISTON_OUTPUT_MAX_SIZE env var in docker compose.